Add missing ATA_ID_* defines and update {ata,atapi}_*()
inlines accordingly. The currently unused defines are
needed for the forthcoming drivers/ide/ changes.
v2:
Add ATA_ID_SPG.
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
The exported copy of videodev2.h contains this line:
#define #include <sys/time.h>
This is because for some reason it defines __user for itself -- despite
the fact that we remove all instances of __user when exporting headers.
_All_ pointers in userspace are user pointers. Fix it by removing the
unnecessary '#define __user' from the file.
The new headers ivtv.h and ivtvfb.h would have the same problem... if
whoever put them there had actually remembered to add them to the Kbuild
file while he was at it. Fix those too, and export them as was
presumably intended.
Note that includes of <linux/compiler.h> are also stripped by the header
export process, so those don't need to be conditional.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Try to comment away a little of the confusion between mm's vm_area_struct
vm_flags and vmalloc's vm_struct flags: based on an idea by Ulrich Drepper.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves it to being a tty operation. That removes special cases and now
also means that resize can be picked up by um and other non vt consoles
which may have a resize operation.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
m68k fails to build with these functions inlined in completion.h. Move
them out of line into sched.c and export them to avoid this problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add __ftrace_enabled_save/restore, used to disable ftrace for a while.
Now, this is used by kexec jump, which need a version without lock, for
general situation, a locked version should be used.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE, because control
page is used for not only code on some platform. For example in kexec
jump, it is used for data and stack too.
[akpm@linux-foundation.org: unbreak powerpc and arm, finish conversion]
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WARNING: vmlinux.o(.text+0xe684): Section mismatch in reference from the function register_nosave_region() to the function .init.text:__register_nosave_region()
The function register_nosave_region() references
the function __init __register_nosave_region().
This is often because register_nosave_region lacks a __init
annotation or the annotation of __register_nosave_region is wrong.
register_nosave_region calls __init function and is called only from
__init functions
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the setting of PF_SUPERPRIV by __capable() as it could corrupt the flags
the target process if that is not the current process and it is trying to
change its own flags in a different way at the same time.
__capable() is using neither atomic ops nor locking to protect t->flags. This
patch removes __capable() and introduces has_capability() that doesn't set
PF_SUPERPRIV on the process being queried.
This patch further splits security_ptrace() in two:
(1) security_ptrace_may_access(). This passes judgement on whether one
process may access another only (PTRACE_MODE_ATTACH for ptrace() and
PTRACE_MODE_READ for /proc), and takes a pointer to the child process.
current is the parent.
(2) security_ptrace_traceme(). This passes judgement on PTRACE_TRACEME only,
and takes only a pointer to the parent process. current is the child.
In Smack and commoncap, this uses has_capability() to determine whether
the parent will be permitted to use PTRACE_ATTACH if normal checks fail.
This does not set PF_SUPERPRIV.
Two of the instances of __capable() actually only act on current, and so have
been changed to calls to capable().
Of the places that were using __capable():
(1) The OOM killer calls __capable() thrice when weighing the killability of a
process. All of these now use has_capability().
(2) cap_ptrace() and smack_ptrace() were using __capable() to check to see
whether the parent was allowed to trace any process. As mentioned above,
these have been split. For PTRACE_ATTACH and /proc, capable() is now
used, and for PTRACE_TRACEME, has_capability() is used.
(3) cap_safe_nice() only ever saw current, so now uses capable().
(4) smack_setprocattr() rejected accesses to tasks other than current just
after calling __capable(), so the order of these two tests have been
switched and capable() is used instead.
(5) In smack_file_send_sigiotask(), we need to allow privileged processes to
receive SIGIO on files they're manipulating.
(6) In smack_task_wait(), we let a process wait for a privileged process,
whether or not the process doing the waiting is privileged.
I've tested this with the LTP SELinux and syscalls testscripts.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (47 commits)
usb: musb: pass configuration specifics via pdata
usb: musb: fix hanging when rmmod gadget driver
USB: Add MUSB and TUSB support
USB: serial: remove CONFIG_USB_DEBUG from sierra and option drivers
USB: Add vendor/product id of ZTE MF628 to option
USB: quirk PLL power down mode
USB: omap_udc: fix compilation with debug enabled
usb: cdc-acm: drain writes on close
usb: cdc-acm: stop dropping tx buffers
usb: cdc-acm: bugfix release()
usb gadget: issue notifications from ACM function
usb gadget: remove needless struct members
USB: sh: r8a66597-hcd: fix disconnect regression
USB: isp1301: fix compilation
USB: fix compiler warning fix
usb-storage: unusual_devs entry for Nokia 5300
USB: cdc-acm.c: Fix compile warnings
USB: BandRich BandLuxe C150/C250 HSPA Data Card Driver
USB: ftdi_sio: add support for PHI Fisco data cable (FT232BM based, VID/PID 0403:e40b)
usb: isp1760: don't be noisy about short packets.
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (56 commits)
netns: Fix crash by making igmp per namespace
bnx2x: Version update
bnx2x: Checkpatch compliance
bnx2x: Spelling mistakes
bnx2x: Minor code improvements
bnx2x: Driver info
bnx2x: 1G LED does not turn off
bnx2x: 8073 PHY changes
bnx2x: Change GPIO for any port
bnx2x: Pause settings
bnx2x: Link order with external PHY
bnx2x: No LRO without Rx checksum
bnx2x: Wrong structure size
bnx2x: WoL capability
bnx2x: Clearing MAC addresses filters
bnx2x: Delay in while loops
bnx2x: PBA Table Page Alignment Workaround
bnx2x: Self-test false positive
bnx2x: Memory allocation
bnx2x: HW attention lock
...
Use platform_data to pass musb configuration-specific
details to musb driver.
This patch will prevent that other platforms selecting
HAVE_CLK and enabling musb won't break tree building.
The other parts of it will come when linux-omap merge
up more omap2/3 board-files.
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds support for MUSB and TUSB controllers
integrated into omap2430 and davinci. It also adds support
for external tusb6010 controller.
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1121) fixes a bug in the USB serial core. When a device
is unregistered, the core will give back its minors -- even if the
device hasn't been assigned any!
The patch reserves the highest minor value (255) to mean that no minor
was assigned. It also removes some dead code and does a small style
fixup.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1117) adds a kerneldoc line for the "needs_binding"
field in struct usb_interface. It was accidentally omitted when the
field was added.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The patches that are intended to introduce copy-on-write credentials for 2.6.28
require abstraction of access to some fields of the task structure,
particularly for the case of one task accessing another's credentials where RCU
will have to be observed.
Introduced here are trivial no-op versions of the desired accessors for current
and other tasks so that other subsystems can start to be converted over more
easily.
Wrappers are introduced into a new header (linux/cred.h) for UID/GID,
EUID/EGID, SUID/SGID, FSUID/FSGID, cap_effective and current's subscribed
user_struct. These wrappers are macros because the ordering between header
files mitigates against making them inline functions.
linux/cred.h is #included from linux/sched.h.
Further, XFS is modified such that it no longer defines and uses parameterised
versions of current_fs[ug]id(), thus getting rid of the namespace collision
otherwise incurred.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
* git://oss.sgi.com:8090/xfs/linux-2.6: (45 commits)
[XFS] Fix use after free in xfs_log_done().
[XFS] Make xfs_bmap_*_count_leaves void.
[XFS] Use KM_NOFS for debug trace buffers
[XFS] use KM_MAYFAIL in xfs_mountfs
[XFS] refactor xfs_mount_free
[XFS] don't call xfs_freesb from xfs_unmountfs
[XFS] xfs_unmountfs should return void
[XFS] cleanup xfs_mountfs
[XFS] move root inode IRELE into xfs_unmountfs
[XFS] stop using file_update_time
[XFS] optimize xfs_ichgtime
[XFS] update timestamp in xfs_ialloc manually
[XFS] remove the sema_t from XFS.
[XFS] replace dquot flush semaphore with a completion
[XFS] replace inode flush semaphore with a completion
[XFS] extend completions to provide XFS object flush requirements
[XFS] replace the XFS buf iodone semaphore with a completion
[XFS] clean up stale references to semaphores
[XFS] use get_unaligned_* helpers
[XFS] Fix compile failure in xfs_buf_trace()
...
XFS object flushing doesn't quite match existing completion semantics. It
mixed exclusive access with completion. That is, we need to mark an object as
being flushed before flushing it to disk, and then block any other attempt to
flush it until the completion occurs. We do this but adding an extra count to
the completion before we start using them. However, we still need to
determine if there is a completion in progress, and allow no-blocking attempts
fo completions to decrement the count.
To do this we introduce:
int try_wait_for_completion(struct completion *x)
returns a failure status if done == 0, otherwise decrements done
to zero and returns a "started" status. This is provided
to allow counted completions to begin safely while holding
object locks in inverted order.
int completion_done(struct completion *x)
returns 1 if there is no waiter, 0 if there is a waiter
(i.e. a completion in progress).
This replaces the use of semaphores for providing this exclusion
and completion mechanism.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31816a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Various cleanup the drivers/firmware/memmap (after review by AKPM):
- fix kdoc to conform to the standard
- move kdoc from header to implementation files
- remove superfluous WARN_ON() after kmalloc()
- WARN_ON(x); if (!x) -> if(!WARN_ON(x))
- improve some comments
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Collect the implementations from include/linux/byteorder/swab.h, swabb.h
in swab.h
The functionality provided covers:
u16 swab16(u16 val) - return a byteswapped 16 bit value
u32 swab32(u32 val) - return a byteswapped 32 bit value
u64 swab64(u64 val) - return a byteswapped 64 bit value
u32 swahw32(u32 val) - return a wordswapped 32 bit value
u32 swahb32(u32 val) - return a high/low byteswapped 32 bit value
Similar to above, but return swapped value from a naturally-aligned pointer
u16 swab16p(u16 *p)
u32 swab32p(u32 *p)
u64 swab64p(u64 *p)
u32 swahw32p(u32 *p)
u32 swahb32p(u32 *p)
Similar to above, but swap the value in-place (in-situ)
void swab16s(u16 *p)
void swab32s(u32 *p)
void swab64s(u64 *p)
void swahw32s(u32 *p)
void swahb32s(u32 *p)
Arches can override any of these with an optimized version by defining an
inline in their asm/byteorder.h (example given for swab16()):
u16 __arch_swab16() {}
#define __arch_swab16 __arch_swab16
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Short enough reads from /proc/irq/*/smp_affinity return -EINVAL for no
good reason.
This became noticed with NR_CPUS=4096 patches, when length of printed
representation of cpumask becase 1152, but cat(1) continued to read with
1024-byte chunks. bitmap_scnprintf() in good faith fills buffer, returns
1023, check returns -EINVAL.
Fix it by switching to seq_file, so handler will just fill buffer and
doesn't care about offsets, length, filling EOF and all this crap.
For that add seq_bitmap(), and wrappers around it -- seq_cpumask() and
seq_nodemask().
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Paul Jackson <pj@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The legacy i2c model is going away soon, so switch to the new model.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Petr Vandrovec <VANDROVE@vc.cvut.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
.. since a failed allocation is being (initially) handled gracefully, and
panic()-ed upon failure explicitly in the function if retries with smaller
sizes failed.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
fix spinlock recursion in hvc_console
stop_machine: remove unused variable
modules: extend initcall_debug functionality to the module loader
export virtio_rng.h
lguest: use get_user_pages_fast() instead of get_user_pages()
mm: Make generic weak get_user_pages_fast and EXPORT_GPL it
lguest: don't set MAC address for guest unless specified
* 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6:
agp: fix SIS 5591/5592 wrong PCI id
intel/agp: rewrite GTT on resume
agp: use dev_printk when possible
amd64-agp: run fallback when no bridges found, not when driver registration fails
intel_agp: official name for GM45 chipset
The kernel has this really nice facility where if you put "initcall_debug"
on the kernel commandline, it'll print which function it's going to
execute just before calling an initcall, and then after the call completes
it will
1) print if it had an error code
2) checks for a few simple bugs (like leaving irqs off)
and
3) print how long the init call took in milliseconds.
While trying to optimize the boot speed of my laptop, I have been loving
number 3 to figure out what to optimize... ... and then I wished that
the same thing was done for module loading.
This patch makes the module loader use this exact same functionality; it's
a logical extension in my view (since modules are just sort of late
binding initcalls anyway) and so far I've found it quite useful in finding
where things are too slow in my boot.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Hello Rusty,
The entropy device was added after we exported all virtio headers. This
patch adds virtio_rng.h to the exportable userspace headers.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.
Export the symbol to modules so lguest can use it.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Inserting a space between the `-' improved the C readability (some languages
allow hyphens within functions and variable names, which is confusing).
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
On my Intel chipset (965GM), the GTT is entirely erased across
suspend/resume. This patch simply re-plays the current mapping at resume
time to restore the table.=20
I noticed this once I started relying on persistent GTT mappings across VT
switch in our GEM work -- the old X server and DRM code carefully unbind
all memory from the GTT on VT switch, but GEM does not bother.
I placed the list management and rewrite code in the generic layer on the
assumption that it will be needed on other hardware, but I did not add the
rewrite call to anything other than the Intel resume function.
Keep a list of current GATT mappings. At resume time, rewrite them into
the GATT. This is needed on Intel (at least) as the entire GATT is
cleared across suspend/resume.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Keith Packard <keithp@keithp.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched, cpu hotplug: fix set_cpus_allowed() use in hotplug callbacks
sched: fix mysql+oltp regression
sched_clock: delay using sched_clock()
sched clock: couple local and remote clocks
sched clock: simplify __update_sched_clock()
sched: eliminate scd->prev_raw
sched clock: clean up sched_clock_cpu()
sched clock: revert various sched_clock() changes
sched: move sched_clock before first use
sched: test runtime rather than period in global_rt_runtime()
sched: fix SCHED_HRTICK dependency
sched: fix warning in hrtick_start_fair()
* 'for-linus' of git://git.o-hand.com/linux-mfd:
mfd: tc6393 cleanup and update
mfd: have TMIO drivers and subdevices depend on ARM
mfd: TMIO MMC driver
mfd: driver for the TMIO NAND controller
mfd: t7l66 MMC platform data
mfd: tc6387 MMC platform data
mfd: Fix 7l66 and 6387 according to the new mfd-core API
mfd: Fix tc6393 according to the new tmio.h
mfd: driver for the TC6387XB TMIO controller.
mfd: driver for the T7L66XB TMIO SoC
mfd: TMIO MMC structures and accessors.
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
powerpc: Remove include/linux/harrier_defs.h
powerpc: Do not ignore arch/powerpc/include
powerpc: Delete completed "ppc removal" task from feature removal file
powerpc/mm: Fix attribute confusion with htab_bolt_mapping()
powerpc/pci: Don't keep ISA memory hole resources in the tree
powerpc: Zero fill the return values of rtas argument buffer
powerpc/4xx: Update defconfig files for 2.6.27-rc1
powerpc/44x: Incorrect NOR offset in Warp DTS
powerpc/44x: Warp DTS changes for board updates
powerpc/4xx: Cleanup Warp for i2c driver changes.
powerpc/44x: Adjust warp-nand resource end address
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI: Limit VPD length for Broadcom 5708S
PCI PM: Export pci_pme_active to drivers
PCI: remove duplicate symbol from pci_ids.h
PCI: check the return value of device_create_bin_file() in pci_create_bus()
PCI: fully restore MSI state at resume time
DMA: make dma-coherent.c documentation kdoc-friendly
PCI: make pci_register_driver() a macro
PCI: add Broadcom 5708S to VPD length quirk
certain configs produce:
[ 70.076229] BUG: MAX_LOCKDEP_KEYS too low!
[ 70.080230] turning off the locking correctness validator.
tune them up.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It was only used by code in arch/ppc, and arch/ppc is gone, so remove
the unused harrier_defs.h as well.
Signed-off-by: Paul Mackerras <paulus@samba.org>
There is a overflow by 1 case in the new shrunken hlock code.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
the names were too generic:
drivers/uio/uio.c:87: error: expected identifier or '(' before 'do'
drivers/uio/uio.c:87: error: expected identifier or '(' before 'while'
drivers/uio/uio.c:113: error: 'map_release' undeclared here (not in a function)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Expose the new lock protection lock.
This can be used to annotate places where we take multiple locks of the
same class and avoid deadlocks by always taking another (top-level) lock
first.
NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On Fri, 2008-08-01 at 16:26 -0700, Linus Torvalds wrote:
> On Fri, 1 Aug 2008, David Miller wrote:
> >
> > Taking more than a few locks of the same class at once is bad
> > news and it's better to find an alternative method.
>
> It's not always wrong.
>
> If you can guarantee that anybody that takes more than one lock of a
> particular class will always take a single top-level lock _first_, then
> that's all good. You can obviously screw up and take the same lock _twice_
> (which will deadlock), but at least you cannot get into ABBA situations.
>
> So maybe the right thing to do is to just teach lockdep about "lock
> protection locks". That would have solved the multi-queue issues for
> networking too - all the actual network drivers would still have taken
> just their single queue lock, but the one case that needs to take all of
> them would have taken a separate top-level lock first.
>
> Never mind that the multi-queue locks were always taken in the same order:
> it's never wrong to just have some top-level serialization, and anybody
> who needs to take <n> locks might as well do <n+1>, because they sure as
> hell aren't going to be on _any_ fastpaths.
>
> So the simplest solution really sounds like just teaching lockdep about
> that one special case. It's not "nesting" exactly, although it's obviously
> related to it.
Do as Linus suggested. The lock protection lock is called nest_lock.
Note that we still have the MAX_LOCK_DEPTH (48) limit to consider, so anything
that spills that it still up shit creek.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Most the free-standing lock_acquire() usages look remarkably similar, sweep
them into a new helper.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
this can be used to reset a held lock's subclass, for arbitrary-depth
iterated data structures such as trees or lists which have per-node
locks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
